<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>table布局,不推荐</title>
</head>
<style>
    table{
        width: 100%;
        border-collapse: collapse;/*边框合并*/
    }
    td{
        border: 1px solid orange;
        padding: 10px;
    }
    .sidebar{
        width: 20%;
        background-color: pink;
    }
    .main{
        width: 60%;
        background-color: aqua;
    }
</style>
<body>
    <table>
        <tr>
            <td class="sidebar">左侧栏</td>
            <td class="main">主要内容</td>
            <td class="sidebar">右侧栏</td>
        </tr>
    </table>
</body>
</html>